The British director's new film 12 Years A Slave tells the story of a free man, played by Chiwetel Ejiofor, who is kidnapped and forced to work on a plantation. Steve said he made the movie to fill the gap he saw.

He explained: "For me there was a hole in the canon of cinema. When you look at films, there's been more films about Spartacus and Roman slaves than there has been about slavery in the United States. Slavery in the United States lasted 400 years and for me that story wasn't being portrayed and I wanted to portray it."

The film - which also stars Lupita Nyong'o, Brad Pitt, Michael Fassbender and Benedict Cumberbatch - includes harrowing scenes of abuse and torture of slaves.

Asked which was the hardest to film Steve said: " Every day was tough to shoot because we were in 160 degree heat, it was very, very hot.

"It's not about which is tough, which is not, it's about the emotion. That's what the difficulty is - the emotion.

"But we had an amazing cast and crew, from the caterers to hair and make-up, to the sound department, to the camera department. That was our base, that was our foundation for the actors to risk and fail and experiment.